What is the element for the electron configuration [Kr] 5s^2 4d^8?

To determine which element corresponds to the given electron configuration of [Kr] 5s² 4d⁸, we start by analyzing the configuration itself.

The notation [Kr] denotes that the electron configuration builds upon the noble gas krypton, which accounts for the first 36 electrons. The notation after krypton, 5s² 4d⁸, indicates that there are additional electrons filling the 5s and 4d subshells. Specifically, this configuration adds two electrons to the 5s subshell and eight electrons to the 4d subshell.

Counting the total number of electrons present in the configuration, we have:

• From [Kr]: 36 electrons

• From 5s²: 2 electrons

• From 4d⁸: 8 electrons

Adding these together gives a total of 36 + 2 + 8 = 46 electrons. The element with 46 electrons is palladium (Pd), which confirms that the correct electron configuration corresponds to palladium.

The other elements listed have different numbers of electrons:

• Silver (Ag) has 47 electrons and would typically have the configuration [Kr] 5s¹ 4d¹⁰.